1. Field of the Invention
The present invention relates to an SFP (Small Form Factor Pluggable) module mounting structure, and in particular to an SFP module mounting structure where an SFP module connected to a connector mounted on a printed board (hereinafter, occasionally referred to as PT board) is held by a holder or a cage (hereinafter, collectively referred to as a holder).
2. Description of the Related Art
A prior art technology related to such an SFP module mounting structure is shown in FIGS. 7A–7C. As shown in FIG. 7A, firstly at a designing stage, a machined hole 1a for a locking portion (not shown) of an SFP module is provided to a PT board 1 for mounting the SFP module.
Thereafter, as shown in FIG. 7B, a holder 50 for holding the SFP module is mounted on the PT board 1, and an SFP module 4 (not shown) is inserted into the holder 50. A state where the SFP module 4 is extracted is virtually shown by dotted lines. As seen from this state, at the time of inserting and extracting the SFP module 4, it is required to reserve a region R1 (shown by hatching) for the portion of a stroke. This region R1 is an area where other components cannot be mounted thereon.
The state shown by solid lines in FIG. 7B is configured by a procedure shown in FIG. 7C at the following manufacturing stage:
(1) Firstly, a lower holder 52 is mounted on the PT board 1. The lower holder 52 has a side face 52a, a bottom face 52b and a connecting pin 52c with standoffs.
(2) The SFP module 4 is inserted from above along the lower holder 52, fitted into a connector 2, and then covered with an upper holder 51.
(3) The SFP module 4 is locked into a locking portion 52d that is a part of the bottom face 52b of the lower holder 52 to be secured, so that the SFP module 4 is held.
It is to be noted that as a technology related to such a prior art technology, there is an electric connector receptacle cage having the upper holder and the lower holder shown in FIG. 7C unified so as to have the SFP module inserted therein (see e.g. patent document 1).
[patent document 1]
                U.S. Pat. No. 6,655,995 B1        
In the prior art technology shown in FIGS. 7A–7C, the SFP module is mounted on the PT board by the combination of the upper holder and the lower holder, so that there has been a problem that the process of further covering the SFP module with the upper holder after having the SFP module inserted into the lower holder is required, and that the region R1 excluding the other components as shown in FIG. 7C is required when the SFP module 4 is extracted from such a holder composed of an upper holder and a lower holder.
Also, by covering the SFP module with the upper holder, the thermal (heat) dissipation of the SFP module is impaired, so that it becomes disadvantageous in terms of heat.